Pyrrolopyrimidine vasodilators and method of making them



The present application relates to a new group of pyrrolo(2,3-d)py1imidines bearing amino groups in the 4-position of the pyrrolo(2,3-d)pyrimidine ring system and is a continuation in part of our US. applications Serial No. 602,912, filed August 8, 1956 and 721,104, filed March 13, 1958. The new derivatives may be represented by the following formula:

R4 23R. M 1

wherein R and R are selected from the class consisting of hydrogen and lower alkyl groups, R is selected from the class consisting of hydrogen and lower alkyl groups,

R; is selected from the class consisting of alkyl, aralkyl,

alkoxyalkyl, dialkoxyalkyl, dialkylaminoalkyl and hydroxyalkyl, and R and R together form a piperazino ring, R and R together containing a maximum of ten carbon atoms.

The new derivatives are useful for their pharmacological activities, in particular for their hypotensive effects. They also have muscle relaxant, hypnotic and anticonvulsant activities. In hypotensive activity they are quite potent and show activities at small fractions of the toxic doses which lie in the neighborhood of 100 mg./kg. Doses in the range of 0.5 to 4 mg./kg. produce falls in systolic blood pressure of dogs of from 5 to 45 mm. of mercury, lasting up to 1.5 hours. These effects appear to be produced or at any rate accompanied by peripheral vasodilation. Coronary vasodilation is also a prominent feature of their effects. A number of applications of these findings will be apparent to those versed in the art.

The new substances are formed by the reaction of a 4 chloropyrrolo(2,3 d)pyrimidine with an appropriate amine to give the 4-amino derivative:

N/ i l R.

wherein R R R and R have the values assigned above. The 4-chloro derivatives are described in US. application 602,912 and two additional intermediates 7-methy1-, and 2-methyl-4-chloropyrrolo(2,3-d)pyrimidine are described herein. The 4-chloropyrrolo(2,3-d)pyrimidinesare the subject of a divisional application of these applicants.

The compounds having R as a hydrogen atom may also be prepared by catalytic dethiolation of the corre- United States Patent 0 M rated to a thick oil on the steam bath. The oil crystal-' 3,037,980 Patented June 5, 1962 sponding mercapto compounds of the formula:

The compounds having R as a hydrogen atom may also be prepared from the corresponding 5-(2,2-dialkoxyethyl) -6-aminopyrimidines by closure of the pyrrole ring with elimination of two molecules of alkanol.

The following examples illustrate the methods used in the preparation of the new substances.

EXAMPLE 1 4 -n-Pr0pylamin0pyrr0l0 (2,3-d )Pyrimidine To 1.3 grams of 4-chloropyrrolo(2,3-d)pyrimidine (0.0085 mole) in 30 ml. of absolute ethanol containing one drop of concentrated hydrochloric acid was added 2.5 ml. of n-propylamine (0.02 mole). The solution was heated in a metal bomb at C. for 7 hours. The bomb was cooled and its contents were evaporated to dryness on the steam bath. The residual thick oil was triturated with 5 cc. of 2.5% sodium hydroxide and allowed to stand at room temperature until crystallization occurred. Thus, 1.2 grams of crude product was obtained by filtration. This was recrystallized from aqueous ethanol (30%) with added Darco. The compound melted at 162 C.

EXAMPLE 2 2-Methyl-4-n-A mylaminopyrrolo (2,3-d) Pyrimidine A solution of ethyl a(2,2-diethoxyethyl)cyanoacetate (11.4 g.) in 25 ml. of ethanol was mixed with a solution of acetamidine (from 4.3 g. of acetamidine hydrochloride and 1.15 g. sodium metal in 25 m1. ethanol) and the resultant solution was heated at reflux temperature for 6 hours. The 4-amino-5-diethoxyethyl-6-hydroxy-2- methylpyrimidine was recovered by evaporation of the solvent, addition of aqueous acetic acid to pH 5.0 and filtration.

The product was dissolved in 100 ml. of 95% alcohol, 2 ml. of concentrated sulfuric acid were added and the solution was heated under reflux for 6 hours. The mixture was chilled and the 4-hydroxy-2-methylpyrrolo- (2,3-d) pyrimidine was recovered by filtration.

To 0.9 grams of 2-methyl-4-chloropyrrolo(2,3-d)- pyrimidine (0.0054 mole) in 25 ml. of absolute ethanol containing one drop of concentrated hydrochloric acid was added 2.4 ml. of n-amylamine (0.016 mole). The solution was heated at C. for 7 hours in a metal bomb. The bomb was cooled and its contents evapo lized upon trituration with 5 cc. of 2.5% sodium hydroxide and yielded 1.1 grams of product after filtering and drying over calcium chloride in a dessicator. The product was recrystallized from 25% aqueous ethanol with added Darco with melting point of 157-159" C .EXAMPLE 3 4-n-Amylamin0-7-Methylpyrr0l0(2,3-d)Pyrimidine reaction flask was sealed and allowed to stand at room temperature for 24 hours, following which it was heated at 45 C. ,for 3-4 hours. Thesuspension was diluted with an equal volume of water, chilled, allowed to stand overnight and filtered to yield 4.1 grams of desired product melting at 130 C. (75% yield)."

To 1 g. of 4-chloro-7-methylpyrrolo(2,3-d)pyrimidine in 25 mlJof ethanol (absolute) were added 1 drop of concentrated hydrochloric acid and 1.5 ml. of n-arnylamine. .The solution was heated in a bomb at 130 C.

After cooling to 15 C., 0.95 grams for 6 hours. After, cooling, the contents of the bomb were evaporated to dryness and the solid was tritur'aited with sodium hydroxide. 'Ihey'recrystallized by solution in hot benzene followed by the addition of hexane to a permanent turbidity. On chilling the material Crystal- 7 It melted at 125;

lined and was recovered by filtration.

By the method of Example 1, the following additional pyrrolo(2,3-d)-pyrimidines have been prepared: V

Example: 7 M.P. f C.

25. 4 (2 methoxyethylamino)pyrrolo- (2,3-d)pyrimidine 167-168 26. 2 methyl 4-1 (2 methoxyethylamino)-pyrrolo(2,3-d)pyrimidine 144-146 27. 4 (3 methoxypropylamino)pyrrolo- (2,3-d)pyri=midine 1 144-145 .28. 4]- dimethylaminopyrrolo(2,3 d)pyrimidine 222 29. 4 methylethylarninopyrrolo(2,3'- d)- pyrimidine 1 70 30. 4 inethyl n propylaminopyrrolofl,

3-d)pyrimidine 148-149 31. 4 methylisopropylaminopyrrolo(2,3- d)pyrimidine 156-157 32. 4 diethylaminopyrrolo(2,3 d)pyrimidine 7 174-175 33. 4 di n propylaminopyrrolo(2,3-d)

pyrimidine 118 34. 4 piperidinopyrrolo(2,3'- d)-pyrirnidine, melting to a clear oil at 184-185 crystallized from heptane. crystallized from benzene-heptane as in Example 3. c Crystallized from benzene. I

' EXAMPLE 35 4-n-Nonylaminopyrrolo(2,3-d)Pyrimidine 4-ch-loropyrro1o(2,3-d)pyrimidine (1.2 g.) and n-nonylamine (5 g.) were refluxed in water (50 ml.) for 2 hours. The mixture was treated with 5% aqueous sodium hydroxide (4 ml.), chilled for two hours, and filtereda After drying in the dessicator, the solid (2.55

. vg.) was recrystallized from hot aqueousethanol yielding 4-n-nonylaminopyrrolo(2,3-d)pyrimidine (2 g.), melting point 122-124 C., as a hemihydrate.

EXAMPLE 36 2-Methyl-4-Benzylaminopyrl olo(2,3-a')Pyrimidine 2 methyl 4 chloropyrrolo(2,3 d) pyrimidine (1.0

g.) and henzylamine (4.0 g.) were refluxed in water ml.) for 3 hours. Ethanol was slowly added, while heating, until complete solution was attained. The solution was chilled overnight and 2-methyl-4-benzylaminopyrrolo(2,3-d)pyrimidine (1.4g), melting point 205- 207 C., was filtered off.

EXAMPLE 37 Z-Meihyl-4-N'-Methylpiperazin0pyrrolo(2,3- V d)Pyrimidine 2-methyl-4-ch1oropyrro1o(2,3-d)pyrimidine 2.0 g.) and N-amethylpiperazine (5.0 g.) wererefluxed in water (65 ml.) for 2 hours. Then potassium hydroxide (3 g.)

i was added and when dissolved the clear solution was chilled overnight yielding a primary crop (2 g.) of 2- w liquor.

EXAMPLE 38 4-N'-Erhylpiperazin0pyrr0l0(2,3-d) Pyrimidine 4-chloropyrrolo(2,3-d)pyrimidine (1.2 g.) and N-ethylpiperazine (4 g.) were heated in water (50 ml.) at -90" C. for 2 hours. Then potassium hydroxide (3.5 g.) was dissolved in the reaction mixture and the solution was chilled overnight. Upon filtration 4-N'-ethy1- piperazinopyrrolm2,3-d)pyrimidine (1.5 g.) was obrained as a dihydrate. Drying for 1.5 hours at C. gave a hemihydrate. The compound changed in crystalline form at 150-160 C. and melted toya clear oil a at 175 0.

MP. C. Example: p 4

- 4. 4 methylaminopyrrolo (2,3 d)

pyrimidine 236 5. 4 dimethylaminopyrrolo(2,3 d)pyrimidine 222 6. 4 ethylaminopyrrolo(2,3, d)pyrirniidine 7. 4 ethyhnethylaminopyrrolo(-2,3 d)- pyrimidine 170 '8. 4 n amylaminopyrrolo(2,3 d)pyrimidine 129 e 9. 4 iso propylaminopyrrolo(2,3 d)

pyrimidine 169-170 10. 4 methylpropylaminopyrrolo(2,3-d)-' 1 pyrimidine 148-149 11. 4, -hydroxyethylaminopyrrolo(2,3 d)- pyrimidine 209 12- 4 diethoxyethylaminopyrro1o(2,3 d)- pyrimidine 124-126 13. 4 no butylarninopyrrolo(2,3. e d)- pyrimidine -146 14. 4 isobutylaminopyrr0lo(2,3 d) pyrirnidine 173-174 .15. 4 sec buty1aminopyrrolo(2,3 d)- pyrimidine 125-126 16. tert hutylaminopyrrolo(2,3 d) pyrimidine I83 17. 4 iso amylarninopyrro1o(2,3 d)- I i I pyrimidine-. 166-167 18. '4'- sec arnylaminopyrrolo(2,3 d)- pyrimidine 140-141 19. 4 n hexylaminopyrrolo(2,3 d)- pyrimidine -151 20. 4 -n heptylaminopyrrolo(2,3 d)- pyrimidine 126-127 v 21. 4 n octylaminopyrrolo(2,3 d)- pyrimidine 118-119 22. 4 n ally1aminopyrrolo(2,3 d)- pyrimidine 167 23. 4 diethylaminoethylaminopyrrolo(2,

3-d)pyrimidine 146-147 24. 4 cyclopentylaminopyrrolo(2,3 -'d)- pyrimidine 162-16 The following compounds were prepared, from the appropriate amine and a 4-chloropyrrolo(2,3-d) pyrirnidine by methods similarto those described in Examples 35 to 38.

C. 39. 4 n hexylaminopyrrolo(2,3-d)pyrimidine 150-151 40. 4 isohexylaminopyrrolo(2,3 d)pyrirnidine 129-130 41. 4 n heptylaminopyrrolo(2,3 d)pyrimidine a 135 42. 4 n octylaminopyrrolo(2,3 d)pyrimidine a 118-119 43. 2 phenyl 4 n nonylaminopyrrolo(2,

3-d)pyrimidine 126-138 44. 4 n decylaminopyrrolo(2,3 d)pyrimidine 110-111 45. 4 cyclohexylaminopyrrolo(2,3 d)pyrirnidine 149-151 46. 4 benzylaminopyrrolo(2,3 d)pyrimidine 196 47. 2 methyl 4 p methylbenzylaminopyrrolo(2,3-d)pyrimidine 211 48. 4 (2 phenylethylamino)pyrrolo(2,3-d)- pyrimidine 197-198 The hydrochloride melted at 231-234 49. 4 (2 dimethylaminoethylamino)pyrrolo- (2,3-d)pyrimidine 164-165 50. 4 (2 diethylaminoethylamino)pyrrolo- (2,3-d)pyrimidine 146-147 51. 4 (2 hydroxyethylamin'o)pyri'o1o(2,3-

d)pyrimidine 209 52. 4 (2,2 diethoxyethylamino)pyrrolo(2,3-

d)pyrimidine 124-126 53. 2 methyl 4 (2,2 diethoxyethylamino)- pyrrolo(2,3-d)pyrimidine l 129-130 54. 4 (3,3 diethoxypropylamino)pyrrolo-(2,

aminopyrrolo(2,3-d)pyrimidine 155 59. 4 methyl(3.3 diethoxypropyDaminopyrrolo(2,3-d)pyrimidine 87-89 60. 4 ethylcarboxymethylaminopyrrolo(2,3-

d)-pyrimidine 204 61. 4 morpholinopyrrolo(2,3 d)pyrirnidine 215 Crystallized from heptane. b Crystallized from benzene-heptane as in Example 3.

The following compounds weer prepared from the appropriate amine and a 4-chloropyrrolo(2,3-d)pyrimidine by methods similar to those described in Examples 1 to 3.

C. 62. 2 methyl 4 ethylaminopyrrolo(2,3-d)- pyrimidine 189-190 63. 4 ethylamino 7 methylpyrrolo(2,3-d)- pyrimidine 159 64. 4 methyl n amylaminopyrrolo(2,3,d)-

pyrimidine 133-135 The following compounds were prepared from the appropriate amine and a 4-chloropyrrolo(2,3-d)pyrimidine by methods similar to those described in examples C. 65. 2 methyl 4 n nonylaminopyrrolo(2,3-

d)pyrimidine 110-113 66. 2 methyl 4 (2 phenylethylamino)pyrrolo(2,3-d)pyn'midine 208-209 67. 4 N methylpiperazinopyrrolo(2,3-d)pyrimidine 142 'The following compounds were prepared from ammonia and the appropriate 4-chloropyrrolo(2,3-d)pyrimidine by methods similar to that described in Example 64.

. C. 68. 2 methyl 4 aminopyrrolo(2,3 d)pyrimidine 290-295 EXAMPLE 69 O C. 70. 2 methyl 4 (3' methoxy)propylaminopyrro'lo(2,3-d)pyrimidine 188-189 71. 2 methyl 4 (2 pyridylmethyl)aminopyrrolo(2,3-d)pyrimidine 215-216 72. 2 methyl 4 (3,4',5'-trimethoxybenzy1) aminopyrrolo(2,3-d)pyrimidine 216-217 73. 2 methyl 4 (3' methylbenzyl) aminopyrrolo(2,3 d)pyrirnidine base 184-185 Hydrochloride salt 230-236 74. 4 (2' thenylamino) pyrrolo(2,3 d)- pyrirnidine 75. 4 (o chlorobenzylamino)pyrrolo(2,3-d)- pyrimidine 220-222 76. 4 p methylbenzylaminopyrrolo(2,3-d)- pyrimidine 203-205 77. 4 N methyl N benzylaminopyrrolo- (2,3-d)pyrimidine 228-230 78. 4 (p chorobenzylamino)pyrrolo(2,3-

d)pyrimidine 205-206 79. 4 (p methoxybenzylamino)pyrrolo(2,3-

d)pyrimidine 236-239 80. 4 methyl n nonylaminopyrrolo(2,3-

d)pyrimidine -106 81. 4 m methylbenzylaminopyrrolo(2,3-

d)pyrimidine 82. 4 o methylbenzylaminopyrrolo(2,3 -d)- pyrimidine 83. 4 (2 pyridyl)methylaminopyrrolo(2,3-

d)pyrimidine 84. 4 diethanolaminopyn-olo(2,3 d)-pyrimidine 196-198 85. 2 n propyl 4 n nonylaminopyrrolo- (2,3 -d) pyrimidine 86. 7 methyl 4 n nonylaminopyrrolo(2, 3-d)pyrimidine hydrochloride 87. 2,7 dimethyl 4 benzylaminopyrrolo- (2,3-d)pyrimidine 88. 4 (4' methylpiperazino) 7 methylpyrrolo(2,3-d)pyrimidine hydrochloride, etlervescence at -210 C.; residue melts at 233-238 C. 89. 2 n propyl 4 benzylaminopyrrolo- (2,3-d)pyrimidine 161-162 90. 2 n propyl 4 (4' ethylpiperazino)- pyrrolo(2,3-d)pyrimidine 91. 4 (4' isopropyl)piperazinopyrrolo(2,

3-d)pyrimidine 178-179 92. 4 (4' n propyl)piperazinopyrrolo(2, 3d)pyrimidine 93. 4 4 oarbethoxy)piperazinopyrro'lo(2,

3-d)pyrimidine 204-205 94. 4 (4' ,8 hydroxyethyDpiperazinopyrrolo(2,3-d)pyrimidine 95. 4 (4 n butyl)pipe1'azinopyrrolo(2,

3-d)pyrirn-idine 171-172 96. 4 (33435 trimethybpiperazinopyrrolm a-a monia 206.201

97. 4 (4 ethyl)piperazinopyrrolo(2,3-d)- pyrimidinefmethiodidenn; 225-230 98. 4 n octy1oxy-pyrro1o(.2,3-d)pyrimidine 107-109 99. 4 n octylmercaptopyrrolo(2,3-d)-pyv rimidine 111-112 py1aminopyrrolo(2,3-d)pyrimidine 139-140 103. 2 methyl 4 methyl n propylaminopyrrolo(2,3-.d) pyrimidine 123-125 104. 2 methylpyrrolo(2,3 -d)pyrimidine 179-180 105. 2 -mcthyl 4 (4 n propylpiperazino I pyrrolo(2,3-d)pyrimidine 194-196 106. 2 methyl 4 (B phenyhethylaminopyrrolo(2 3 -d)pyrimidine base 208-209 Hydrochloride salt 112-116 '107. 2 methyl 4 (p chlorobenzy1amino)- pyrrolo(2,3-d)pyri midine 219-222 30 111. 2 methyl 4 (or. furfurylamino)-pyr rolo(2,3-d)pyrimidine (change in crystalline form above 160 C.) V 195-197 What we claim is:

pyrrold(2,3-d)pyrimidine 234-235 108. 2 methyllf 4 (N methylbenzylamino)- 25 pyr-roltr(2, 3-d)pyritrlidinc 218-219 109. 2.- methyl 4 (2 thenylamino)pyrrolo(2,3d)pyrimidine 214-215 110. 2 methyl 4 (o chlorobenzylamino)- 1. A compound of the formula:

wherein R and R are selected from the class consisting of hydrogen and lower alkyl groups, R is selected from the class consisting of hydrogen and lower alkyl groups, R; is selected from the classrconsi-sting of alkyl, phenylalkyl, alkoxyalkyl, dialkoxyalkyl, dialkylaminoalkyl and hydroxyalkyl, and R and R together form a piperazino ring, R and R together containing a maximum of ten carbon atoms.

2. 4-(methyl-n-propylamino)pyrrol0(2,3-d)pyrimidine.

3. 2-methyl-4-benzylaminopyrro1o(2,3-d)pyrimidine.

4. 4-n-nonylaminopyrrolo(2,3-d)pyrimidine.

5. 2-methyl-4-(4-methy1piperazino)pyrrolo(2,3-d)pyrimidine.

6. 2-methyl-4-(2'-methoxyethyl)amjnopyrrolo(2,3-d)a pyrimidine.

7. 4-diethoxyethylaminopyrrolo(2,3-cl)pyrimidine.

8. 4-ethy1aminopyrrolo(2,3-d)pyrim.idine.

9. 4-n-propy1aminopyrrolo(2,3-d)pyrimidine. 10. 4-methoxymethylaminopyrro1o(2,3-d)pyrimidine.

11. 4-tert-hutylaminopyrrolo(2,3-d)pyrimidine.

No references cited.

no; .em 

1. A COMPOUND OF THE FORMULA: 